The present invention relates to a sliding-caliper disk brake located on a fixed brake carrier. The invention also relates to a brake pad set of a disk brake of said type.
Force-transmitting components of such disk brakes are normally produced in one-piece form by a primary forming process, preferably in a sand casting process. The material used is preferably cast iron with spheroidal graphite or nodular cast iron. The cast blank thus produced subsequently undergoes a cutting finish machining process, such that, for example, an installable brake carrier or an installable brake caliper is produced. Such one-piece brake carriers or brake calipers composed of nodular cast iron according to the prior art have basically proven successful, but have certain disadvantages which have an adverse effect in particular in the field of use of heavy utility vehicles.
For example, the brake carriers or brake calipers according to the prior art, owing to the strength demands on the brake carrier and owing to a restricted structural space for the brake carrier and the resulting previous geometric design, have a weight which may be improved upon.
Also mentioned here is European patent publication no. EP 0 139 890 A1, which discloses, inter alia, brake pads of different size.
It is thus desirable—in particular also with regard to the optimization of the payload of a utility vehicle—to provide a weight-optimized and cost-optimized brake carrier and a weight-optimized and cost-optimized brake caliper, in particular for utility vehicle brakes, which overcomes the disadvantages mentioned above.
The invention is therefore based on the object of creating an improved disk brake having a weight-optimized and cost-optimized brake carrier and a weight-optimized and cost-optimized brake caliper.
It is a further object of the invention to provide a brake pad set for a disk brake of said type.
The invention achieves said objects by a relatively wide brake pad slot on a reaction side of the brake carrier, wherein it is advantageously possible for the volume of the reaction-side brake pad to be made larger than the volume of the application-side brake pad. This gives rise to further advantages such as, for example, improved heat dissipation in the direction of the brake caliper rear section, such that the application mechanism of the disk brake, and in particular the seals thereof, are conserved. Furthermore, the resulting tilting moment that acts on the brake caliper during the braking process is reduced, because the pressure point of the reaction-side brake pad is advantageously changed.
A disk brake according to the invention, in particular sliding-caliper disk brake, comprises at least one positionally fixed brake carrier which has two pairs of carrier horns by which a reaction-side brake pad and an application-side brake pad are held, a brake caliper which is formed by tension struts and by a brake caliper rear section, and an application mechanism. The spacing between the carrier horns which receive the reaction-side brake pad is greater than the spacing between the carrier horns which receive the application-side brake pad.
In one embodiment, the carrier horns on a reaction side of the brake carrier are of shorter form than those on an application side of the brake carrier. The shortening of the carrier horns results in a lower bending moment that acts on the foot of a carrier horn during braking, such that the respective shortened carrier horn exhibits less deformation, or less mechanical stress, than in the prior art.
In a further embodiment, a volume of the reaction-side brake pad is greater than a volume of the application-side brake pad. The reduction in thickness of the reaction-side brake pad makes it possible to reduce a structural space on the reaction side of the brake caliper, which can be filled in order to realize targeted stiffening of the brake caliper rear section and of the tension struts of the brake caliper.
If the thickness of the reaction-side brake pad is maintained, greater performance, or a longer service life, of the reaction-side brake pad is realized. This is desirable because the reaction-side brake pad, owing to its position and the associated exposure to dirt, conventionally wears more quickly than the application-side brake pad during the operation of the disk brake. Furthermore, the enlarged reaction-side brake pad absorbs more heat, such that the specific release of heat from the reaction-side brake pad can likewise be increased, and, correspondingly, more heat can be discharged into the brake caliper rear section. This conserves the application mechanism, in particular the seals thereof.
In a yet further embodiment, it is provided that connecting points between the tension struts and the brake caliper rear section are rounded with a three-center curve or with an elliptical segment. By these geometric measures, it is furthermore the case that a stress level is correspondingly lowered, which has an advantageous effect in the weight balance of the brake caliper. For this purpose, in a further embodiment, the tension struts may each have an optimized geometry which narrows toward the brake caliper rear section and which finally opens into the three-center curve or into the elliptical segment.
In one embodiment, the optimized geometry with the three-center curves at the sides forms a type of elliptical opening of the brake caliper rear section of the brake caliper, wherein an application-side longitudinal side of the opening of the brake caliper rear section is shorter than a reaction-side longitudinal side of the opening of the brake caliper rear section. This yields advantageously straightforward confusion-free installation of the brake pads during maintenance or during new installation. The geometry of the opening prevents the relatively wide brake pad from being installed in place of the relatively short brake pad, and thus predefines the correct installation location.
A resultant tilting moment which acts on the brake caliper rear section during a braking process can be reduced by way of the geometry of the reaction-side brake pad. This, too, can have a positive influence on a structural size.
In one embodiment, the brake carrier and the brake caliper are produced by way of a casting process. Here, a ductile cast material may be used for the brake carrier and the brake caliper. A cast iron with spheroidal graphite is also possible. Combinations of these various materials are also conceivable.
In a further embodiment, the reaction-side brake pad and the application-side brake pad and the two pairs of carrier horns each bear against one another at support surfaces. Clear guidance and confusion-free installation are thus possible.
A brake pad set according to the invention of a disk brake as described above has a first brake pad and a second brake pad. The first brake pad has a width greater than a width of the second brake pad. This firstly permits confusion-free installation. Secondly, a resultant tilting moment on the brake caliper rear section can be reduced. Likewise, the service life of the two brake pads can be influenced such that uniform wear is achieved.
In one embodiment, the first brake pad has a volume greater than a volume of the second brake pad. It is thereby possible to influence an absorption of heat in the presence of different levels of heat generation.
Furthermore, the first brake pad is provided as a reaction-side brake pad for the associated disk brake, and the second brake pad is provided as an application-side brake pad for the associated disk brake. It is thus possible for the different geometries of the brake pads to serve for a uniform force distribution.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.